Repair device

ABSTRACT

This repair device includes a casing, a slide shaft slidably arranged with respect to the casing, a turn table rotatably arranged with respect to the slide shaft, and a cutting mechanism installed on the turn table and including cutting tools. The turn table is rotationally displaced while the slide shaft slides in an axial direction, so that the cutting tools helically turn to cut an inner periphery of a nozzle. The cutting mechanism includes a cutting-tool switching unit that switches the cutting tools.

FIELD

The present invention relates to a repair device, and more particularlyto a repair device that can streamline a repairing operation.

BACKGROUND

In a nuclear plant, a repairing operation for repairing a welded partbetween a nozzle and a pipe in a reactor containment is performed toensure safety and reliability thereof. As a repair device used for sucha repairing operation, a technique described in Patent Literature 1 hasbeen known.

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent Application Laid-open No.2006-349596

SUMMARY Technical Problem

An object of the present invention is to provide a repair device thatcan streamline a repairing operation.

Solution to Problem

According to an aspect of the present invention, a repair device thatrepairs a welded part on an inner peripheral side of a pipe, includes: acasing; a slide shaft slidably arranged with respect to the casing; aturn table rotatably arranged with respect to the slide shaft; and acutting mechanism installed on the turn table and including a pluralityof cutting tools for cutting the welded part. The turn table isrotationally displaced while the slide shaft slides in an axialdirection, so that the cutting tools helically turn to cut an innerperiphery of the pipe, and the cutting mechanism includes a cutting-toolswitching unit that switches the cutting tools.

In this repair device, the cutting tools helically turn to cut the innerperiphery of the pipe. Therefore, when an area to be cut is wide,replacement of the cutting tools becomes necessary. At this time, thecutting mechanism performs cutting while replacing the cutting tools bythe cutting-tool switching unit, thereby enabling to continue a cuttingoperation, with the repair device being installed in the pipe.Accordingly, a repairing operation is streamlined.

Advantageously, in the repair device, the cutting-tool switching unitincludes a switching-unit main body installed on a side of the turntable, a cutting-tool support body that supports the cutting tools andswitches the cutting tools by a rotational displacement, and a drivemechanism that is connected to the cutting-tool support body via aratchet mechanism. Further, when the drive mechanism is driven in apredetermined forward direction, the ratchet mechanism engages to rotatethe cutting-tool support body, and when the drive mechanism is driven inan opposite direction, the ratchet mechanism restricts rotations of thecutting-tool support body.

According to this repair device, when the drive mechanism is driven in apredetermined forward direction, the ratchet mechanism engages to rotatea fitted rotating shaft. Accordingly, the cutting-tool support body isrotated to enable switching of the cutting tools. On the other hand,when the drive mechanism is driven in the opposite direction, theratchet mechanism restricts rotations of the fitted rotating shaft.Accordingly, the drive mechanism returns to an initial position withoutswitching the cutting tools 41.

Advantageously, in the repair device, the cutting-tool switching unitincludes a fixing structure that supplies fluid to between the fittedrotating shaft and the switching-unit main body and presses the fittedrotating shaft to the switching-unit main body, thereby fixing thefitted rotating shaft.

According to this repair device, a fluid pressure is applied between thefitted rotating shaft and the switching-unit main body, thereby fixingthe cutting-tool support body to the switching-unit main body via thefitted rotating shaft. Furthermore, by releasing the fluid pressure, thecutting-tool support body can be rotated, thereby enabling to switch thecutting tools. Therefore, fixing and releasing of the cutting-toolswitching unit can be performed with a simple configuration.

Advantageous Effects of Invention

According to the repair device of the present invention, cutting toolshelically turn to cut an inner periphery of a pipe. Therefore, when anarea to be cut is wide, replacement of the cutting tools becomesnecessary. At this time, the cutting mechanism performs cutting whilereplacing the cutting tools by the cutting-tool switching unit, therebyenabling to continue a cutting operation, with the repair device beinginstalled in the pipe. Accordingly, a repairing operation isstreamlined.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a repair device according to anembodiment of the present invention.

FIG. 2 is an axial sectional view of the repair device shown in FIG. 1.

FIG. 3 is a plan view of a turn table of the repair device shown in FIG.1.

FIG. 4 is a front view of the turn table of the repair device shown inFIG. 1.

FIG. 5 is a side view of the turn table of the repair device shown inFIG. 1.

FIG. 6 is a flowchart of an entire-perimeter cutting process performedby the repair device shown in FIG. 1.

FIG. 7 is an explanatory diagram of the entire-perimeter cutting processperformed by the repair device shown in FIG. 1.

FIG. 8 is an explanatory diagram of the entire-perimeter cutting processperformed by the repair device shown in FIG. 1.

FIG. 9 is an explanatory diagram of the entire-perimeter cutting processperformed by the repair device shown in FIG. 1.

FIG. 10 is a plan view of a cutting mechanism of the repair device shownin FIG. 1.

FIG. 11 is a sectional view of the cutting mechanism shown in FIG. 10 asviewed from an arrow B.

FIG. 12 is a sectional view of the cutting mechanism shown in FIG. 11 asviewed from an arrow C.

FIG. 13 is an explanatory diagram of a function of the cutting mechanismshown in FIG. 10.

FIG. 14 is an explanatory diagram of a function of the cutting mechanismshown in FIG. 10.

FIG. 15 is an explanatory diagram of a function of the cutting mechanismshown in FIG. 10.

FIG. 16 is an explanatory diagram of a function of the cutting mechanismshown in FIG. 10.

FIG. 17 is a flowchart of a repairing process of a reactor containment.

FIG. 18 is an explanatory diagram of a welded part between a nozzle anda pipe in the reactor containment.

FIG. 19 is an explanatory diagram of a state of local cutting.

DESCRIPTION OF EMBODIMENTS

The present invention is explained below in detail with reference to theaccompanying drawings. The present invention is not limited to thefollowing embodiment. In addition, constituent elements in theembodiment include elements that can be easily replaced or obviouslyreplaceable while maintaining the unity of invention. A plurality ofmodifications described in the following embodiment can be arbitrarilycombined within a scope obvious to persons skilled in the art.

[Repairing Process of Reactor Containment]

FIG. 17 is a flowchart of a repairing process of a reactor containment.FIG. 18 is an explanatory diagram of a welded part between a nozzle anda pipe in the reactor containment.

In a reactor containment 100, maintenance is regularly performed toensure safety and reliability thereof. For example, the reactorcontainment 100 includes a nozzle 120 provided on a side of an outerperiphery of a containment main body 110 and a cooling water pipe (aninlet pipe or an outlet pipe) 130 (see FIG. 18). The nozzle 120 and thepipe 130 have a substantially cylindrical inner periphery and areconnected by welding from at least one of the inner peripheral side andthe outer peripheral side. Generally, the nozzle 120 and the pipe 130are made of a material different from each other, and welded by nickelbased alloy 600. Maintenance such as a repairing operation is requiredfor a welded part between the nozzle 120 and the pipe 130. As anexample, a case where a repairing operation is performed at a weldedpart X on the inner peripheral side of the nozzle 120 and the pipe 130is explained.

First, as a preparation step (Step ST1), a work table 140 having acylindrical container shape is inserted into the containment main body110 and installed therein. The work table 140 transports various typesof repair devices required for a repairing operation (an inspectiondevice, a cutting device, a welding device, and a buff device describedlater) into the nozzle 120, and has an opening 141 at a positioncorresponding to the nozzle 120. A gap between the containment main body110 and the work table 140 is then sealed and joined by using a flange.Subsequently, cooling water below the flange is discharged, and a waterlevel of cooling water is set such that the water level becomes at leastbelow the nozzle 120 of the containment main body 110 (see FIG. 17 andFIG. 18). A shield 150 is inserted into the nozzle 120 from the opening141 of the work table 140 and installed therein. The shield 150 is amember that fills a gap between the opening 141 of the work table 140and the nozzle 120 and extends the opening 141 to the inner periphery ofthe nozzle 120. The shield 150 forms a cylindrical inner wall surface(an installation space of the repair device) extending from the opening141 of the work table 140 to the welded part X of the nozzle 120. Astopper (not shown) is installed on an inner side of the pipe 130 toform a seal for blocking radiation and preventing dispersion of foreignsubstances.

Next, a device-transporting jig (not shown) is installed (Step ST2). Thedevice-transporting jig transports the repair device and is installed atthe bottom of the work table 140. For example, the device-transportingjig is formed by a turn table having a telescopic arm. When the repairdevice is transported into the welded part X, the repair device issuspended in the work table 140, and the device-transporting jigtransports the repair device into the nozzle 120 and installs the repairdevice in the nozzle 120. At this time, the device-transporting jigholds the repair device by the arm, and extends the arm to insert therepair device into the nozzle 120 from the opening 141 of the work table140. Accordingly, the repair device is transported into the nozzle 120.Thereafter, the device-transporting jig is detached from the repairdevice, contracts the arm, and is returned to an original position. Onthe other hand, when the repair device is to be removed from the weldedpart X, the device-transporting jig extends the arm again to hold therepair device in the nozzle 120, contracts the arm, and recovers therepair device into the work table 140. The repair device is then hoistedand transported to outside of the work table 140. With these processes,transporting in/out of the repair device is performed.

Next, an ultrasonic testing (UT) using ultrasonic waves is performed(inspection step ST3). The UT is a test for acquiring required data ofthe welded part X (for example, data relating to the presence andposition of a defect in the welded part X). At Step ST3, an inspectiondevice for performing the UT (not shown) is transported in by thedevice-transporting jig and installed near the welded part X of thenozzle 120. The inspection device performs the UT to acquire necessaryinspection data. For example, the inspection data includes a position ofthe welded part X, a position of a large crack generated in the weldedpart X (a crack requiring local cutting described later) and the like.The acquired inspection data is transmitted from the inspection deviceto a controller (not shown) in a monitoring facility located outside ofthe reactor containment 100. Furthermore, the inspection device punchesa mark near the welded part X, for indicating the position of the weldedpart X or the position of a crack. Thereafter, the inspection device istransported out of the nozzle 120 and then recovered.

Next, local cutting is performed according to need (local cutting stepST4). FIG. 19 is an explanatory diagram of a state of a local cutting.The local cutting is for locally and deeply cutting a cracked portion inthe welded part X, when there is a large crack in the welded part X. Inthe local cutting, a cutter 10 for cutting is used (see FIG. 19). Thecutter 10 is a rotatable tool formed by arranging a plurality of cuttingtools in a circumferential direction. The cutter 10 is fitted to thecutting device (or another repair device) and used. At Step ST4, first,the cutting device mounted with the cutter 10 is transported into thenozzle 120 by the device-transporting jig, and is installed near thewelded part X of the nozzle 120. After centering is performed withrespect to the inner periphery of the nozzle 120, the cutting device isfixedly installed. The cutting device is then positioned with respect tothe cracked portion in the welded part X based on the inspection dataacquired at Step ST3 (and punching). Subsequently, local cutting isperformed. In the local cutting, the cutter 10 is applied to the crackedportion in the welded part X and rotated, thereby performing localcutting of the welded part X (for example, cutting to a depth up to 49[mm]). Thereafter, the cutting device is transported out of the nozzle120 and then recovered.

When the local cutting (Step ST4) is performed, a weld deposit isproduced as well for filling a locally cut portion.

Next, entire perimeter cutting is performed (entire-perimeter cuttingstep ST5). The entire perimeter cutting is for cutting a certain areaincluding the welded part X to a certain depth over the entire perimeterof the inner periphery of the nozzle 120. At Step ST5, cutting of thewelded part X as a target to be repaired is performed prior to weldingdescribed later. First, the cutting device is transported in by thedevice-transporting jig and installed near the welded part X of thenozzle 120. Centering of the cutting device is then performed withrespect to the inner periphery of the nozzle 120 and fixedly installed.The cutting device is then positioned with respect to the welded part Xin an axial direction of the nozzle 120 based on the inspection dataacquired at Step ST3 (and punching). Subsequently, entire perimetercutting is performed with respect to a certain area including the weldedpart X. Thereafter, the cutting device is transported out of the nozzle120 and then recovered. In the present embodiment, the cutting deviceperforms entire perimeter cutting by using the cutting tools forcutting. A specific configuration of the cutting device and a specificcontent of the entire perimeter cutting are explained later in detail.

Next, welding is performed (welding step ST6). The welding produces aweld deposit in an area having already subjected to the entire perimetercutting (Step ST5). At Step ST6, first, the welding device istransported in by the device-transporting jig and installed near thewelded part X of the nozzle 120. Centering and positioning of thewelding device are then performed. Subsequently, the welding deviceproduces a weld deposit in a locally cut portion (Step ST4). The weldingdevice welds the area having already subjected to the entire perimetercutting (Step ST5) throughout the area. Thereafter, the welding deviceis transported out of the nozzle 120 and then recovered.

Next, finish cutting is performed (finish cutting step ST7). The finishcutting is for performing finish cutting to an area already welded (StepST6). At Step ST7, first, the cutting device is transported in by thedevice-transporting jig and installed near the welded part X of thenozzle 120. Centering and positioning of the cutting device are thenperformed. Subsequently, the cutting device performs finish cutting tothe area already welded (Step ST6). The finish cutting is performed inthe same manner as in the entire perimeter cutting (Step ST5). In thepresent embodiment, the cutting device also serves as the buff device asdescribed later. Therefore, the cutting device (the repair device) isnot recovered from the nozzle 120, and directly performs the next stepST8.

Next, buffing is performed (buffing step ST8). This buffing is forperforming buffing to the area having subjected to the finish cutting(Step ST7), and an object thereof is to reduce a residual stress in thewelded part X. At Step ST8, because the cutting device also serves asthe buff device as described later, an installation step, a centeringstep, and a positioning step of the buff device are omitted. The buffdevice then performs buffing to the area having subjected to the finishcutting (Step ST7). Thereafter, the buff device (also serves as thecutting device) is transported out of the nozzle 120 and then recovered.

In a general reactor containment 100, the containment main body 110 hasa plurality of nozzles 120 (see FIG. 18). Therefore, in the welded partsX of these nozzles 120, a series of steps of from Step ST3 to Step ST8are performed respectively. In the present embodiment, a repair device 1described later includes a clamp mechanism 3, and thus the repair device1 is installed in the nozzle 120 in a self-standing manner. With thisconfiguration, a plurality of repair devices 1 are respectivelyinstalled in each of the nozzles 120, so that a repairing operation isperformed for each of the nozzles 120 independently from each other.Accordingly, the repairing operation is performed efficiently. Thisfeature is explained later.

Next, the device-transporting jig is hoisted and recovered from the worktable 140 to outside of the containment main body 110 (Step ST9).Thereafter, the shield 150 is removed from the nozzle 120, and the worktable 140 is removed (Step ST10). Accordingly, a repairing operation ofthe welded part X is complete.

[Repair Device of Reactor Containment]

FIG. 1 is a perspective view of the repair device according to theembodiment of the present invention. FIG. 2 is an axial sectional viewof the repair device shown in FIG. 1. FIGS. 3 to 5 are respectively aplan view (FIG. 3), a front view (FIG. 4), and a side view (FIG. 5) of aturn table of the repair device shown in FIG. 1.

The repair device 1 repairs a welded part on the inner peripheral sideof a pipe, and is used for a repairing operation of, for example, thewelded part X between the nozzle 120 and the pipe 130 of the reactorcontainment 100 on the inner peripheral side thereof (see FIG. 18). Therepair device 1 includes a drive mechanism 2, the clamp mechanism 3, acutting mechanism 4, a buff mechanism 5, an advancing and retractingmechanism 6, a laser sensor 81, and an image sensor 82. Therefore, therepair device 1 includes both functions of a cutting device and a buffdevice, and can perform entire perimeter cutting (Step ST5), finishcutting (Step ST7), and buffing (Step ST8).

The drive mechanism 2 includes a casing 21, a slide shaft 22, a rotatingshaft 23, a turn table 24, a slide shaft actuator 25, and a rotatingshaft actuator 26 (see FIGS. 1 and 2).

The casing 21 is made of a substantially cylindrical member. Centeringand positioning of the casing 21 are performed with respect to the innerwall surface of the nozzle 120, thereby performing centering andpositioning of the repair device 1.

The slide shaft 22 is slid and displaced in an axial direction (a Ydirection) with respect to the casing 21, and has a hollow structure.The slide shaft 22 is inserted into the casing 21, and is connected tothe casing 21 via the slide shaft actuator 25 in the casing 21. Theslide shaft actuator 25 has a slider mechanism. The slide shaft actuator25 is constituted by a guide rail 251 laid on an outer periphery of theslide shaft 22, a slider 252 fixedly installed on the inner periphery ofthe casing 21, and a servomotor (not shown) that drives the slider 252.The slide shaft 22 is driven by the slide shaft actuator 25, and is slidand displaced in the axial direction with respect to the casing 21. Theservomotor is connected to a controller in a monitoring center anddrive-controlled. For example, the slide shaft 22 has a stroke of 200[mm], and can be slid and displaced in a speed range of 0 [mm/s] to 2[mm/s].

The rotating shaft 23 is rotationally displaced about the slide shaft 22(in a 01 direction). The rotating shaft 23 is inserted into a hollowpart of the slide shaft 22, and is rotatably supported by a pair ofbearings 221, 221 in the slide shaft 22. The rotating shaft 23 includesa flange 231 at one end thereof, and is connected to the rotating shaftactuator 26 on an outer periphery of the flange 231. For example, therotating shaft actuator 26 is a servomotor, and is installed on a sideof the slide shaft 22. In the present embodiment, a flange 222 is formedat one end of the slide shaft 22, and the rotating shaft actuator 26 isfitted to the flange 222. The rotating shaft 23 is driven by therotating shaft actuator 26, and is rotationally displaced about theslide shaft 22. The rotating shaft actuator 26 is connected to thecontroller in the monitoring center and drive-controlled. For example,the rotating shaft 23 can be rotationally displaced in a rotationalspeed range of 0 [rpm] to 14 [rpm].

The turn table 24 is a rotating table for installing the cuttingmechanism 4, the buff mechanism 5, and the advancing and retractingmechanism 6 thereon. The turn table 24 is fixedly installed to theflange 231 of the rotating shaft 23 and rotates together with therotating shaft 23. For example, in the present embodiment, the turntable 24 has a circular table shape, and a leg thereof is fixedlyinstalled to the flange 231, with a table surface thereof being directedto the axial direction of the rotating shaft 23. For example, the turntable 24 rotates at a constant speed together with the rotating shaft23.

The clamp mechanism 3 clamps the inner wall surface of the nozzle 120 tofix the casing 21 inside the nozzle 120 (see FIG. 1). A plurality ofclamp mechanisms 3 are installed as a set on the outer periphery of thecasing 21. For example, in the present embodiment, four clamp mechanisms3 at opposite ends of the casing 21, in total, eight clamp mechanisms 3are arranged with a gap of about 90 degrees. For example, the clampmechanism 3 is formed by connecting a hydraulic cylinder 31 and a clamp33 via a linking unit 32 (see FIG. 1). In the clamp mechanism 3, whenthe cylinder 31 is driven by remote control, the clamp 33 is driven viathe linking unit 32 and displaced in a radial direction of the casing21. The clamp 33 is pressed against the inner wall surface of the nozzle120 to clamp the inner wall surface, thereby fixing the casing 21 in thenozzle 120. Because the clamp mechanisms 3 are driven by remote controlto adjust an amount of displacement of the clamp 33 reciprocally, aposition of the casing 21 with respect to the inner periphery of thenozzle 120 is adjusted. Accordingly, a centering operation of the repairdevice 1 (the casing 21) is performed. The cylinder 31 of the clampmechanism 3 is connected to the controller in the monitoring center anddrive-controlled.

The cutting mechanism 4 performs cutting (entire perimeter cutting) overthe entire inner periphery of the nozzle 120 (see FIG. 1 and FIGS. 3 to5). The cutting mechanism 4 includes a cutting tool 41 for cutting. Thecutting mechanism 4 is fitted to the advancing and retracting mechanism6 described later, and installed near an edge on the turn table 24. Inthe cutting mechanism 4, when the turn table 24 is rotated, the cuttingtool 41 turns about an axis of rotation (in the 01 direction) of theturn table 24 to cut the inner periphery of the nozzle 120 (rotationalcutting). At this time, the cutting mechanism 4 is driven by theadvancing and retracting mechanism 6 and slid and displaced in apredetermined direction (an R direction) on the turn table 24, therebychanging a cutting depth thereof. An operation of the cutting mechanism4 is explained later in detail.

The buff mechanism 5 performs buffing with respect to the welded part Xof the nozzle 120 (see FIG. 1 and FIGS. 3 to 5). The buff mechanism 5includes a buff 51 and a drive part 52 for rotating the buff 51.Furthermore, the buff mechanism 5 is fitted to the advancing andretracting mechanism 6 described later and installed near the edge onthe turn table 24. The buff mechanism 5 performs buffing of the innerperiphery of the nozzle 120 by rotating (spinning) the buff 51 andpressing the buff 51 against the inner periphery of the nozzle 120. Theturn table 24 rotates while the buff 51 is rotating, thereby moving(revolving) the position of the buff mechanism 5 about the axis ofrotation (in the θ1 direction) of the turn table 24, to perform buffingwith respect to the entire perimeter of the inner periphery of thenozzle 120. The drive part 52 of the buff mechanism 5 is connected tothe controller in the monitoring center and drive-controlled. Anoperation of the buff mechanism 5 is explained later together with theoperation of the cutting mechanism 4.

The advancing and retracting mechanism 6 causes the cutting mechanism 4and the buff mechanism 5 to be displaced forward and backward on theturn table 24 (see FIG. 1 and FIGS. 3 to 5). For example, in the presentembodiment, the advancing and retracting mechanism 6 is a slidemechanism, and is constituted by a rail 61 laid on the upper surface ofthe turn table 24 and extending in the radial direction (the Rdirection) of the turn table 24, a long slider 62 that is slid anddisplaced along the rail 61, and a servomotor (not shown) that drivesthe slider 62. The advancing and retracting mechanism 6 holds thecutting mechanism 4 and the buff mechanism 5 at the opposite ends of theslider 62. Accordingly, when the advancing and retracting mechanism 6causes the slider 62 to move in one direction, the cutting tool 41 ofthe cutting mechanism 4 protrudes from the turn table 24 or the buff 51of the buff mechanism 5 protrudes from the turn table 24, therebyswitching the cutting mechanism 4 and the buff mechanism 5. Further, theadvancing and retracting mechanism 6 adjusts the amount of displacementof the slider 62 in the R direction, thereby enabling to adjust aprotruding amount of the cutting tool 41 and the buff 51 from the turntable 24. The servomotor of the advancing and retracting mechanism 6 isconnected to the controller in the monitoring center anddrive-controlled. For example, the advancing and retracting mechanism 6has a stroke of 85 [mm], and can be displaced forward and backward in aspeed range of 0 [mm/s] to 15 [mm/s].

The laser sensor 81 measures an inner peripheral shape of the nozzle 120(see FIG. 1 and FIGS. 3 to 5). The laser sensor 81 is installed near theedge of the turn table 24, with an irradiation direction of the laserbeing directed radially outward of the turn table 24. Accordingly, whenthe turn table 24 rotates, the position of the laser sensor 81 is movedabout the axis of rotation of the turn table 24. With thisconfiguration, the laser sensor 81 can measure the inner peripheralshape of the nozzle 120 over the entire perimeter. The laser sensor 81is data-communicably connected to the controller in the monitoringcenter, and transmits an output signal to the controller.

For example, the image sensor 82 is a CCD (Charge Coupled Device) camera(see FIG. 1 and FIGS. 3 to 5). For example, the image sensor 82 isinstalled on a camera stand (not shown) on the turn table 24. The imagesensor 82 can move an imaging direction thereof in a circumferentialdirection of the turn table 24. Accordingly, the image sensor 82 cancapture images of a cutting position of the cutting mechanism 4, abuffing position of the buff mechanism 5, a state inside the nozzle 120and the like from above of the table surface. The image sensor 82 isconnected to a monitor in the monitoring center.

A balancing mechanism 91 is arranged on the turn table 24 (see FIGS. 3and 4). When the cutting mechanism 4 and the buff mechanism 5 aredisplaced by driving the advancing and retracting mechanism 6, thebalancing mechanism 91 suppresses deflection or backlash of theadvancing and retracting mechanism 6 due to an external force tomaintain accuracy in a cutting depth at the time of cutting. Forexample, the balancing mechanism 91 includes an oil hydraulic cylinder,and an oil-circulation flow channel that connects front and rearchambers of the oil hydraulic cylinder via an orifice.

A distribution box 92 and an air nozzle 93 are also arranged on the turntable 24 (see FIGS. 3 to 5). The distribution box 92 accommodates adistribution system for the cutting mechanism 4, the buff mechanism 5,the advancing and retracting mechanism 6, and the balancing mechanism91. The air nozzle 93 injects air and has a function of blowing off cutchips generated in a cutting process, for example. The air nozzle 93 isinstalled respectively on a side of the cutting mechanism 4 and on aside of the buff mechanism 5. Cut chips generated at the time of arepairing operation are sucked by a vacuum pipe (not shown) and thenrecovered at outside of the nozzle 120.

Furthermore, the rotating shaft 23 has a hollow structure, and a slipring 27 is arranged therein (see FIG. 2). The slip ring 27 accommodateswiring (such as electric wiring and signal wiring) to the cuttingmechanism 4, the buff mechanism 5, and the advancing and retractingmechanism 6. The cutting mechanism 4, the buff mechanism 5, and theadvancing and retracting mechanism 6 are connected to the controller inthe monitoring center via such wiring and then drive-controlled.

Further, the rotating shaft 23 includes a plurality of swivel joints 28at an end opposite to the flange 222 (an end positioned on a side of thecontainment main body 110 in a state where the repair device 1 isinstalled) (see FIG. 2). These swivel joints 28 become a channel forsupplying working fluid for the cutting mechanism 4, the buff mechanism5, the advancing and retracting mechanism 6, the balancing mechanism 91,and the air nozzle 93.

[Cutting Performed by Repair Device]

FIGS. 6 to 9 are respectively a flowchart (FIG. 6) of anentire-perimeter cutting process performed by the repair device shown inFIG. 1 and explanatory diagrams thereof (FIGS. 7 to 9). Among thesedrawings, FIG. 7 depicts a state where the repair device 1 is installedin the nozzle 120, and FIGS. 8 and 9 depict a state of cutting thewelded part X.

As mentioned above, the repair device 1 includes both functions of thecutting mechanism and the buff mechanism 5, and can respectively performthe entire perimeter cutting (Step ST5), the finish cutting (Step ST7),and the buffing (Step ST8). As an example, a case where the repairdevice 1 is used as the cutting device to perform the entire perimetercutting (Step ST5) is explained (see FIG. 6).

At the entire perimeter cutting (Step ST5), the repair device 1 istransported in (Step ST51) (see FIG. 7). Specifically, the repair device1 is inserted from the opening 141 of the work table 140 into the nozzle120 and installed near the welded part X.

At this time, the clamp mechanism 3 clamps the inner periphery of thenozzle 120 to fix the repair device 1 (see FIG. 7). Therefore, therepair device 1 is installed in the nozzle 120 in a self-standing mannerwithout any assistance from a side of the work table 140. Accordingly, aplurality of repair devices 1 can be arranged, respectively, in aplurality of nozzles 120 and operated independently from each other,thereby enabling to streamline a repairing operation. Becauseconventional repair devices cannot be installed in the nozzle in aself-standing manner, assistance such as supporting a rear part of therepair device from the side of the work table is required. Therefore,the work table is occupied for assisting one repair device, and thusthere is a problem that repairing operations for a plurality of nozzlescannot be performed simultaneously.

Next, centering of the repair device 1 is performed (centering stepST52). At Step ST52, it is set such that the eight clamp mechanisms 3reciprocally adjust the clamp height of the clamps 33 so that the shaftof the casing 21 and the shaft of the nozzle 120 substantially coincidewith each other. Specifically, it is set so that the shaft of the slideshaft 22 (a Y direction) and the shaft of the nozzle 120 coincide witheach other. The respective clamp mechanisms 3 fix the clamps 33, and therepair device 1 is fixedly installed in a state where centering of therepair device 1 is performed with respect to the nozzle 120.

Next, positioning of the cutting mechanism 4 is performed (positioningstep ST53). At Step ST53, a positional relation between the cuttingmechanism 4 and the welded part X in the axial direction of the nozzle120 is set based on the inspection data acquired at Step ST3 (andpunching). Specifically, the slide shaft 22 slides in the axialdirection (the Y direction) and the turn table 24 moves in the axialdirection of the nozzle 120. With this configuration, it is set so thatthe position of the cutting mechanism 4 on the turn table 24 and theposition of the welded part X achieve a predetermined positionalrelation in the axial direction of the nozzle 120. At this time, imagedata from the image sensor 82 is transmitted to the controller, and thepositional relation between the cutting mechanism 4 and the welded partX is adjusted, while confirming the image data by a monitor of thecontroller.

Next, the inner peripheral shape of the nozzle 120 is measured(inner-peripheral shape measuring step ST54). At Step ST54, the turntable 24 goes around in the 01 direction, and the laser sensor 81measures the inner peripheral shape of the nozzle 120. In thismeasurement, measurement data of at least the opposite ends of an areato be cut (an area subjected to cutting) is respectively acquired.Specifically, the slide shaft 22 is displaced in the Y direction to movea measurement position of the laser sensor 81, thereby acquiring themeasurement data at the opposite ends of the area to be cut. The innerperipheral shape of the nozzle 120 in the entire area to be cut isestimated based on the measurement data. The area to be cut is a certainarea including the welded part X, and a range in the Y direction is setbased on the inspection data acquired at Step ST3.

Next, the repair device performs the entire perimeter cutting withrespect to the area to be cut (entire-perimeter cutting step ST55). AtStep ST55, the turn table 24 is rotated at a predetermined speed. Atthis time, the rotational speed of the turn table 24 is controlled sothat an end of the cutting tool 41 turns at a set speed. The advancingand retracting mechanism 6 then moves the cutting mechanism 4 in theradial direction (the R direction) of the turn table 24, and brings thecutting tool 41 of the cutting mechanism 4 into contact with the innerwall surface of the nozzle 120. The cutting tool 41 then turns in the θ1direction due to the rotations of the turn table 24, to cut the innerperiphery of the nozzle 120 (see FIG. 8). Furthermore, the slide shaft22 is gradually slid and displaced at a certain speed in the axialdirection (the Y direction), so that the cutting tool 41 helically turnswith a narrow pitch, thereby cutting the inner wall surface of thenozzle 120 in a cylindrical shape (entire perimeter cutting). At thistime, the advancing and retracting mechanism 6 is driven and displacedforward and backward in a direction of the inner wall surface of thenozzle 120 (in the R direction). Accordingly, the turning radius of thecutting tool 41 is enlarged or contracted to adjust a cutting depth h(see FIG. 9). The cutting tool 41 can turn in a speed range of 0 [m/min]to 30 [m/min] to perform cutting by rotationally displacing the rotatingshaft 23 in the rotational speed range of 0 [rpm] to 14 [rpm].

The inner peripheral shape of the nozzle 120 is not necessarily a truecircle and, for example, the inner peripheral shape can be elliptical,or can include irregularities, or a bend on the inner wall surface at aweld line. Furthermore, a shaft of the repair device and the shaft ofthe nozzle 120 may be out of alignment. Therefore, at Step ST55, aturning trajectory of the cutting tool 41 is calculated and controlledso that the inner periphery of the nozzle 120 is cut to a certaincutting depth h. Specifically, the turning trajectory of the cuttingtool 41 in the area to be cut is calculated based on a relation betweenthe measurement data (Step ST54) of the inner peripheral shape of thenozzle 120 in the area to be cut and the predetermined cutting depth h.Further, a relation among the rotational speed of the turn table 24 inthe θ1 direction, the sliding speed of the slide shaft 22 in the Ydirection, and forward and backward displacement of the advancing andretracting mechanism 6 in the R direction is calculated based on thecalculation result. The slide shaft 22 and the advancing and retractingmechanism 6 are driven based on the calculation result, to perform theentire perimeter cutting (profile copy cutting). Accordingly, the areato be cut is uniformly cut to the predetermined cutting depth h over theentire perimeter of the inner periphery of the nozzle 120.

Next, the cutting mechanism 4 and the slide shaft 22 are returned toinitial positions, and thereafter the repair device 1 is transported outof the nozzle 120 and then recovered (Step ST56). With this process, theentire perimeter cutting step ST5 is complete.

While the entire perimeter cutting (Step ST5) has been explained as anexample, the finish cutting (Step ST7) is performed in a similar manner(not shown). That is, the relation among the rotational speed of theturn table 24 in the θ1 direction, the sliding speed of the slide shaft22 in the Y direction, and the forward and backward displacement of theadvancing and retracting mechanism 6 in the R direction is calculatedbased on the relation between the measurement data of the innerperipheral shape of the nozzle 120 in the area to be cut (Step ST54) andthe predetermined cutting depth h. The turn table 24, the slide shaft22, and the advancing and retracting mechanism 6 are driven based on thecalculation result, thereby controlling the turning trajectory of thecutting tool 41 in the area to be cut. Accordingly, the area to be cutis uniformly cut to the predetermined cutting depth h, and the finishcutting is appropriately performed.

Furthermore, the buffing (Step ST8) is also performed in a similarmanner (not shown). That is, the relation among the rotational speed ofthe turn table 24 in the θ1 direction, the sliding speed of the slideshaft 22 in the Y direction, and the forward and backward displacementof the advancing and retracting mechanism 6 in the R direction iscalculated based on the relation between the measurement data (StepST54) of the inner peripheral shape of the nozzle 120 in an area to bebuffed (same as the area to be cut) and a pressing force of the buff 51against the inner wall surface of the nozzle 120. The buff 51 helicallyrevolves, while rotating at a predetermined rotational speed, to performappropriate buffing. At this time, the buff 51 buffs the area to bebuffed at an appropriate moving speed by controlling the rotationalspeed of the turn table 24 and the sliding speed of the slide shaft 22.Further, the buff 51 buffs the area to be buffed with an appropriatepressing force, by controlling the forward and backward displacement ofthe advancing and retracting mechanism 6. Accordingly, the area to bebuffed is appropriately buffed.

[Cutting-Tool Switching Unit of Cutting Mechanism]

FIG. 10 is a plan view of a cutting mechanism of the repair device shownin FIG. 1. FIG. 11 and FIG. 12 are respectively a sectional view asviewed from an arrow B (FIG. 11), and a sectional view as viewed from anarrow C (FIG. 12), of the cutting mechanism shown in FIG. 10. FIGS. 13to 16 are explanatory diagrams of a function of the cutting mechanismshown in FIG. 10.

In the repair device 1, the cutting mechanism 4 includes a structurecapable of switching the cutting tools 41. A configuration of thecutting mechanism 4 is explained below.

The cutting mechanism 4 includes a plurality of cutting tools 41, acutting-tool switching unit 42, and a cutting tool table 43 (see FIG.10). The cutting tools 41 are tool bits for cutting, and can beconstituted by the same type or different types. For example, in thepresent embodiment, at the entire-perimeter cutting step ST5, becausethe cutting tools 41 are sequentially changed and used, five cuttingtools 41 of the same type are used. The cutting-tool switching unit 42is a drive mechanism that holds the cutting tools 41 and moves andswitches these cutting tools 41. The cutting-tool switching unit 42 isexplained later in detail. The cutting tool table 43 is a member thatfixes the cutting mechanism 4 to the slider 62 of the advancing andretracting mechanism 6. For example, in the present embodiment, thecutting tool table 43 supports the cutting-tool switching unit 42, andis fixed to the slider 62 of the advancing and retracting mechanism 6.With this configuration, the cutting mechanism 4 and the slider 62 ofthe advancing and retracting mechanism 6 are integrated.

The cutting-tool switching unit 42 includes a switching-unit main body421, a cutting-tool support body 422, a fitted rotating shaft 423, apinion 424, a rack 425, a cylinder 426, a piston 427, a firstpositioning pin 428, and a second positioning pin 429 (see FIG. 11).

The switching-unit main body 421 is a casing having a substantiallycylindrical container shape. The cutting-tool support body 422 holds thecutting tools 41. The cutting-tool support body 422 has a substantiallydisk-like shape, and holds the five cutting tools 41 with an equal gapon an outer peripheral edge on the upper surface side thereof. Thefitted rotating shaft 423 is a rotating shaft of the cutting-toolsupport body 422. The cutting-tool support body 422 and an internalmechanism of the switching-unit main body 421 are connected to eachother via the fitted rotating shaft 423. An upper surface of theswitching-unit main body 421 and a lower surface of the cutting-toolsupport body 422 are made to abut on each other, and the fitted rotatingshaft 423 is inserted into the cutting-tool support body 422 from theupper surface of the cutting-tool support body 422. The fitted rotatingshaft 423 and the cutting-tool support body 422 are coupled by a boltand integrated on the upper surface of the cutting-tool support body422. A flange 4231 is formed on the fitted rotating shaft 423.

The pinion 424 is rotatably fitted to and installed on the fittedrotating shaft 423, with one surface of the pinion 424 abutting on theflange 4231 of the fitted rotating shaft 423. The rack 425 is insertedinto and slidably arranged in the cylinder 426 in the switching-unitmain body 421. The pinion 424 and the rack 425 constitute a rack/pinionmechanism 424, 245. The cylinder 426 is buried in the switching-unitmain body 421. The piston 427 is a member that presses the rack 425 inan axial direction. The piston 427 is connected to an end of the rack425, and is inserted into and arranged in the cylinder 426 together withthe rack 425. When a fluid pressure such as an air pressure is appliedfrom behind, the piston 427 presses the rack 425 in an axial directionat the front by the fluid pressure. The fluid pressure to be applied tothe piston 427 is supplied from outside of the repair device 1 to thecutting mechanism 4 via the swivel joints 28 and the rotating shaft 23(see FIG. 2).

The first positioning pin 428 controls a positional relation between theswitching-unit main body 421 and the cutting-tool support body 422 (seeFIGS. 11 and 13). A ratchet groove 4212 is formed on the upper surfaceof the switching-unit main body 421, and a pin hole 4221 is formed onthe lower surface of the cutting-tool support body 422. The firstpositioning pin 428 is inserted into the pin hole 4221 in thecutting-tool support body 422, and an apex thereof is arranged, engagedwith the ratchet groove 4212 on the switching-unit main body 421. Thefirst positioning pin 428 biases the apex thereof into engagement withthe ratchet groove 4212 by a spring force. Accordingly, the firstpositioning pin 428 and the ratchet groove 4212 engages with each otherto constitute a first ratchet mechanism 428, 4212.

The second positioning pin 429 controls a positional relation betweenthe flange 4231 of the fitted rotating shaft 423 and the pinion 424 ofthe rack/pinion mechanism 424, 245 (see FIGS. 11 and 14). A ratchetgroove 4241 is formed on an upper surface of the pinion 424, and a pinhole 4232 is formed on a lower surface of the flange 4231. The secondpositioning pin 429 is inserted into the pin hole 4232 in the flange4231, and an apex thereof is arranged, engaged with the ratchet groove4241 on the pinion 424. The second positioning pin 429 biases the apexthereof into engagement with the ratchet groove 4241 by a spring force.Accordingly, the second positioning pin 429 and the ratchet groove 4241engages with each other to constitute a second ratchet mechanism 429,4241.

When the pinion 424 rotates in a forward direction, the second ratchetmechanism 429, 4241 is separated to rotate only the pinion 424. When thepinion 424 rotates in an opposite direction, the second ratchetmechanism 429, 4241 engages to connect the pinion 424 to the flange4231. In this example, when the piston 427 is driven in the forwarddirection to rotate the pinion 424, the pinion 424 rotates in theopposite direction. Accordingly, the second ratchet mechanism 429, 4241engages, and the pinion 424 and the flange 4231 rotate together. On theother hand, when the piston 427 is driven in the opposite direction torotate the pinion 424, the pinion 424 rotates in the forward direction.Accordingly, the second ratchet mechanism 429, 4241 is separated andonly the pinion 424 rotates.

Furthermore, the first ratchet mechanism 428, 4212, and the secondratchet mechanism 429, 4241 are respectively formed, corresponding tothe arrangement of the five cutting tools 41 held by the cutting-toolsupport body 422 (see FIG. 15).

In the cutting mechanism 4, switching of the cutting tools 41 isperformed as described below.

In a fixed state of the cutting tools 41, a fluid pressure (for example,a hydraulic pressure) is applied to a predetermined position in theswitching-unit main body 421. For example, in the present embodiment,the fluid pressure is applied to a narrow gap (not shown) between theflange fixed to the fitted rotating shaft 423 and an inner wall surfaceof the switching-unit main body 421. Alternatively, the fluid pressurecan be applied to a narrow gap (not shown) on a bonded surface betweenthe flange fixed to the fitted rotating shaft 423 and the flange fixedin the switching-unit main body 421. The fitted rotating shaft 423 isthen pressed against the switching-unit main body 421 due to the fluidpressure and fixed. Because the cutting-tool support body 422 is fixedon the fitted rotating shaft 423, the cutting-tool support body 422 isfixed with respect to the switching-unit main body 421. With thisconfiguration, the cutting-tool switching unit 42 is fixed with respectto an external force and an internal rotation force, and the cuttingtools 41 become fixed. In this state, the fluid pressure is not appliedto the piston 427.

At the time of switching the cutting tools 41, the hydraulic pressure (ahydraulic pressure applied to a predetermined position in theswitching-unit main body 421) for fixing the cutting tools 41 (thecutting-tool switching unit 42) is released. Accordingly, thecutting-tool switching unit 42 can rotate freely, thereby enabling toswitch the cutting tools 41. Subsequently, the fluid pressure is appliedto the piston 427 (see FIG. 12). Supply of the air pressure to the firstpositioning pin 428 and the second positioning pin 429 is stopped, and alocked state of the first ratchet mechanism 428, 4212 and the secondratchet mechanism 429, 4241 is released. When the piston 427 is drivenin the forward direction due to the fluid pressure, the rack 425 ispressed and moved deep into the cylinder 426 (by a shift amount when onecutting tool 41 is shifted). The pinion 424 rotates due to an engagementwith the rack 425. In this state, the pinion 424 rotates in the oppositedirection. Accordingly, the second ratchet mechanism 429, 4241 engages,and the pinion 424 and the flange 4231 rotate together. The fittedrotating shaft 423 then rotates together with the flange 4231, and thecutting-tool support body 422 rotates together with the fitted rotatingshaft 423 (see FIG. 11). The rotation direction thereof becomes theforward direction with respect to the first ratchet mechanism 428, 4212.Therefore, the cutting-tool support body 422 rotates with respect to theswitching-unit main body 421, and the cutting tools 41 are rotated byone cutting tool. With this process, switching of the cutting tools 41is performed.

The piston 427 returns to the original position due to releasing of afluid pressure. The piston 427 is then driven in the opposite direction,and the rack 425 is returned. The pinion 424 is then rotated due to theengagement with the rack 425. In this state, the pinion 424 is rotatedin the opposite direction. Accordingly, the second ratchet mechanism429, 4241 is separated, and only the pinion 424 rotates. Therefore, thecutting tool 41 remains in a fixed state because the flange 4231 (thefitted rotating shaft 423) does not rotate.

Furthermore, switching of the cutting tools 41 is performed at the timeof a cutting operation (Steps ST5 and ST7). For example, in the repairof the nozzle 120, because the area to be cut may be wide, all areas tobe cut may not be cut only by a single cutting tool 41.

Therefore, the cutting mechanism 4 includes the cutting-tool switchingunit 42 and performs cutting while replacing the cutting tools 41 by thecutting-tool switching unit 42, thereby enabling to continue the cuttingoperation, with the repair device 1 being installed in the nozzle 120.Accordingly, a repairing operation is streamlined.

[Effect 1]

As explained above, the repair device 1 includes the casing 21, theslide shaft 22 slidably arranged with respect to the casing 21, the turntable 24 rotatably arranged with respect to the slide shaft 22, thecutting mechanism 4 installed on the turn table 24 and including thecutting tools 41, and the advancing and retracting mechanism 6 thatdisplaces a radius of rotation of the cutting mechanism 4 with respectto the rotations of the turn table 24 forward and backward (see FIGS. 1to 5). Furthermore, in a state where the casing 21 is centered andpositioned with respect to the pipe (the nozzle 120), the turn table 24is rotationally displaced while the slide shaft 22 slides in an axialdirection, and the advancing and retracting mechanism 6 displaces thecutting mechanism 4 forward and backward. Accordingly, the cutting tools41 helically turn along the inner peripheral shape of the pipe to cutthe inner periphery of the pipe (see FIGS. 6 to 9). In such aconfiguration, rotational cutting by the cutting tools 41 is realized byan interaction among sliding displacement of the slide shaft 22,rotational displacement of the turn table 24, and forward and backwarddisplacement of the buff mechanism 5. Thereby, the area to be cut havinga substantially cylindrical shape can be cut smoothly, thereby improvingcutting accuracy. Accordingly, any aftertreatment is not required, and arepairing operation can be streamlined. For example, in a configurationin which a cutting mechanism helically revolves to perform cutting,while rotating a cutting tool (see Patent Literature 1), aftertreatmentbecomes necessary due to a step generated in a cutting trace.

Furthermore, the repair device 1 includes a measuring unit (the lasersensor 81) that acquires measurement data of the inner peripheral shapeof the pipe (see FIG. 1 and FIGS. 3 to 5). The relation among thesliding speed of the slide shaft 22, the rotational speed of the turntable 24, and forward and backward displacement of the cutting mechanism4 is calculated based on the relation between the acquired measurementdata and the predetermined cutting depth h, to control the turningtrajectory of the cutting tool 41 (see Steps ST54 and ST55 in FIG. 6).In such a configuration, the area to be cut can be cut along the innerperipheral shape of the pipe (profile copy rotational cutting).Accordingly, the area to be cut having a non-uniform shape can be cutaccurately. In such a configuration, the turning trajectory of thecutting tool 41 can be finely adjusted, thereby enabling to simplify acentering operation of the repair device 1 with respect to the nozzle120 (Step ST42). That is, when the repair device 1 is to be installed inthe nozzle 120, centering needs only to be performed in such a degreethat an axis of the slide shaft 22 (the Y direction) and an axis of thenozzle 120 substantially agree with each other, and the positionalrelation between an outer peripheral edge of the turn table 24 and theinner periphery of the nozzle 120 do not need to be strictly determined.

The repair device 1 includes the buff mechanism 5 having the buff 51 forbuffing (see FIG. 1 and FIGS. 3 to 5). The buff mechanism 5 and thecutting mechanism 4 are installed so as to be changed by the turn table24. In such a configuration, because the repair device 1 serves as thebuff mechanism 5 and the cutting mechanism 4, there is an advantage inthat operations related to transporting in/out and installation of thedevice can be omitted, as compared to a configuration in which the buffmechanism and the cutting mechanism are separately used.

In the repair device 1, the advancing and retracting mechanism 6displaces the turning radius of the buff mechanism 5 with respect to therotations of the turn table 24 forward and backward (see FIG. 1 andFIGS. 3 to 5). In such a configuration, buffing can be performed byrevolving the buff 51 helically while in rotation, by an interactionamong sliding displacement of the slide shaft 22, rotationaldisplacement of the turn table 24, and forward and backward displacementof the buff mechanism 5. With this configuration, buffing can besmoothly performed with respect to the area to be buffed having asubstantially cylindrical shape. Particularly, by controlling theturning trajectory of the buff 51 based on the relation between themeasurement data (Step ST54) of the inner peripheral shape of the pipein the area to be buffed and the pressing force of the buff 51 againstthe inner periphery of the pipe, buffing can be appropriately performedwith respect to the area to be buffed with a predetermined pressingforce and a predetermined moving speed.

The repair device 1 includes the clamp mechanism 3 that holds the casing21 in a state where the casing 21 is positioned in the pipe (see FIGS. 1and 7). In such a configuration, because the clamp mechanism 3appropriately holds the position of the casing 21 (particularly, arelative position of the repair device in an axial direction of the pipewith respect to a target to be cut) at the time of controlling theturning trajectory of the cutting tool 41, the repair device 1 isinstalled in the pipe in a self-standing manner. With thisconfiguration, because each of the repair devices 1 can be arranged in aplurality of pipes and individually operated, a repairing operation canbe streamlined.

This repair method includes the inner-peripheral shape measuring step(Step ST54) of acquiring the measurement data of the inner peripheralshape of the pipe, and the cutting step (Step ST55) at which profilecopy cutting is performed with respect to the inner periphery of thepipe, while the cutting tool 41 is being turned helically along theinner peripheral shape of the pipe (see FIGS. 6 to 9). In such aconfiguration, because cutting (profile copy rotational cutting) can beperformed with respect to the area to be cut along the inner peripheralshape of the pipe, the area to be cut having a non-uniform shape can becut accurately. Accordingly, any aftertreatment is not required, andthus a repairing operation can be streamlined.

[Effect 2]

The repair device 1 includes the casing 21, the slide shaft 22 slidablyarranged with respect to the casing 21, the turn table 24 rotatablyarranged with respect to the slide shaft 22, and the cutting mechanism 4installed on the turn table 24 and including the cutting tools 41 (seeFIGS. 1 to 5). Furthermore, the turn table 24 is rotationally displacedwhile the slide shaft 22 slides in an axial direction, so that thecutting tools 41 helically turn to cut the inner periphery of the pipe(the nozzle 120) (see FIGS. 6 to 9). Further, the cutting mechanism 4includes the cutting-tool switching unit 42 that switches the cuttingtools 41 (see FIGS. 10 to 12). In such a configuration, the cuttingtools 41 helically turn to cut the inner periphery. Therefore, when thearea to be cut is wide, the cutting tools 41 need to be replaced. Atthis time, the cutting mechanism 4 performs cutting while replacing thecutting tools 41 by the cutting-tool switching unit 42, thereby enablingto continue a cutting operation, with the repair device 1 beinginstalled in the pipe. Accordingly, a repairing operation can bestreamlined.

In the repair device 1, the cutting-tool switching unit 42 includes theswitching-unit main body 421 installed on a side of the turn table 24,the cutting-tool support body 422 that supports the plurality of cuttingtools 41 and switches the cutting tools 41 by rotational displacement,the fitted rotating shaft 423 connected to the cutting-tool support body422, and the drive mechanism (the piston 427) connected to the fittedrotating shaft 423 via the ratchet mechanism (the second ratchetmechanism 429, 4241) (see FIGS. 11 and 12). In such a configuration,when the drive mechanism (the piston 427) is driven in the predeterminedforward direction, the ratchet mechanism (the second ratchet mechanism429, 4241) engages to rotate the fitted rotating shaft 423. Accordingly,the cutting-tool support body 422 rotates to switch the cutting tools41. On the other hand, when the drive mechanism (the piston 427) isdriven in the opposite direction, the ratchet mechanism (the secondratchet mechanism 429, 4241) restricts rotations of the fitted rotatingshaft 423. Accordingly, the drive mechanism (the piston 427) returns toan initial position without switching the cutting tools 41.

The repair device 1 includes a fixing structure in which thecutting-tool switching unit 42 supplies fluid to between the fittedrotating shaft 423 and the switching-unit main body 421 and presses thefitted rotating shaft 423 against the switching-unit main body 421,thereby fixing the fitted rotating shaft 423 (see FIG. 11). In such aconfiguration, the fluid pressure is applied between the fitted rotatingshaft 423 and the switching-unit main body 421, thereby fixing thecutting-tool support body 422 to the switching-unit main body 421 viathe fitted rotating shaft 423. Furthermore, the cutting-tool supportbody 422 can be rotated by releasing the fluid pressure, therebyenabling to switch the cutting tools 41. Accordingly, fixing andreleasing of the cutting-tool switching unit 41 can be performed with asimple configuration.

INDUSTRIAL APPLICABILITY

As described above, the repair device according to the present inventionis advantageous in a characteristic that a repairing operation can bestreamlined.

REFERENCE SIGNS LIST

1 repair device

2 drive mechanism

21 casing

22 slide shaft

221 bearing

222 flange

23 rotating shaft

231 flange

24 turn table

25 slide shaft actuator

251 guide rail

252 slider

26 rotating shaft actuator

27 slip ring

28 swivel joint

3 clamp mechanism

31 cylinder

32 linking unit

33 clamp

4 cutting mechanism

41 cutting tool

42 cutting-tool switching unit

421 switching-unit main body

4212 ratchet groove

422 cutting-tool support body

4221 pin hole

423 fitted rotating shaft

4231 flange

4232 pin hole

424 pinion

4241 ratchet groove

425 rack

426 cylinder

427 piston

428 first positioning pin

429 second positioning pin

43 cutting tool table

5 buff mechanism

52 drive part

51 buff

6 advancing and retracting mechanism

61 rail

62 slider

81 laser sensor

82 image sensor

91 balancing mechanism

92 distribution box

93 air nozzle

10 cutter

100 reactor containment

110 containment main body

120 nozzle

130 pipe

140 work table

141 opening

150 shield

The invention claimed is:
 1. A repair device that repairs a welded parton an inner peripheral side of a pipe, comprising: a casing; a slideshaft slidably arranged with respect to the casing; a turn tablerotatably arranged with respect to the slide shaft; and a cuttingmechanism installed on the turn table and including a plurality ofcutting tools for cutting the welded part, wherein the turn table isrotationally displaced while the slide shaft slides in an axialdirection, so that the cutting tools helically turn to cut an innerperiphery of the pipe, and the cutting mechanism includes a cutting-toolswitching unit that switches the cutting tools, the cutting-toolswitching unit includes a switching-unit main body installed on a sideof the turn table, a cutting-tool support body that supports the cuttingtools and switches the cutting tools by a rotational displacement, afitted rotating shaft that is connected to the cutting-tool supportbody, and a drive mechanism that is connected to the fitted rotatingshaft via a ratchet mechanism, and the ratchet mechanism engages torotate the fitted rotating shaft when the drive mechanism is driven in apredetermined forward direction, and the ratchet mechanism restrictsrotations of the fitted rotating shaft when the drive mechanism isdriven in an opposite direction.
 2. The repair device according to claim1, wherein the cutting-tool switching unit includes a fixing structurethat supplies fluid to between the fitted rotating shaft and theswitching-unit main body and presses the fitted rotating shaft to theswitching-unit main body, thereby fixing the fitted rotating shaft.